Apparatus and method for advancing catheters or other medical devices through a lumen

ABSTRACT

Devices, systems, and methods are disclosed that help deliver catheters or other medical devices to locations within a patient&#39;s body. The device comprises a transporter catheter having a proximal end and a distal end, at least a first balloon located at the distal end, substantially at a tip of the transporter catheter, and at least a second balloon located between the distal end and the proximal end of the transporter catheter. The first balloon is an orienting balloon and the second balloon is an anchor balloon. The transporter catheter may include a single lumen or more than one lumen. The transporter catheter may include a shaft comprising an inner layer and an outer layer, the inner layer may be made of a material more flexible than the material of the outer layer. The outer layer may also comprise a braided-wire assembly, said braided-wire assembly being formed by braiding a plurality of flat wires or circular wires. The braided-wire assembly may wrap around the inner layer. The transporter catheter may comprise a shaft that may include a plurality of segments of varying degrees of hardness. The degree of hardness of the segment of the shaft of the transporter catheter located between the first balloon and the second balloon may be less than the degree of hardness of the segment of the shaft between the second balloon and the proximal end of the catheter.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of co-pending U.S. patentapplication Ser. No. 16/701,966, filed Dec. 3, 2019, and claims benefitof U.S. Provisional Application No. 62/886,349, filed Aug. 14, 2019; theentire content of the above applications is incorporated herein byreference.

FIELD OF THE INVENTION

The invention relates generally to devices, systems, and methods thathelp deliver catheters or other medical devices to locations within apatient's body. More particularly, the present invention is directed toa transporter catheter, which is located inside an outer catheter, e.g.,a sheath, an introducer catheter, a guide catheter or an inner catheter.An orienting balloon at a tip of the transporter catheter assists in theorientation and positioning of the transporter catheter, and an anchorballoon is used for anchoring the transporter catheter, e.g., anchoringthe transporter catheter to an inner surface of a sheath or anintroducer catheter or a guiding catheter or an inner catheter as theuser maneuvers the system comprising the transporter catheter and thesheath or the introducer catheter or the guiding catheter through thepatient's body.

BACKGROUND OF THE INVENTION

Catheters are used for an ever-growing number of medical proceduresincluding diagnostic and/or therapeutic procedures. To facilitateplacement of the diagnostic and/or therapeutic catheter at a location ofinterest within a patient, a catheter may be introduced through a secondcatheter, which is commonly known as a “sheath” or “introducercatheter,” and these two terms will be used interchangeably herein. Anintroducer catheter is a tube that is used to facilitate the placementof other catheters into specific areas of the patient's body. In thefield of cardiac ablation, for example, introducer catheters may be usedto negotiate the patient's vasculature such that an ablation device maybe passed through and positioned to be able to ablate arrhythmia-causingcardiac tissue. The introducer catheter itself may be advanced over aguidewire.

Complex coronary anatomy including tortuosity, calcification, as well asother structural characteristics of the coronary artery can make transitof hardware through the lumen proximal to a stenosis difficult andsometimes impossible. Several advancements in technology such as stifferguidewires, large bore guide catheters that allow for improved passivesupport, and hydrophilic coatings that provide reduced friction, haveimproved the ability to advance balloons and stents through thesecoronary arteries with some success. Guidewires that allow for dynamicdeflection of the tip such as the “Wiggle” wire have also improvedhardware transit. However, even with these advances, in view of theexpanding indications for percutaneous coronary intervention (“PCI”),there is an unmet need for improving PCI outcomes in complex substrates.

A guide catheter may be located inside an introducer catheter, and aninner support catheter (“daughter” or “child” catheter) placed inside aguide catheter. Advancing the inner support catheter into the coronaryartery deeply intubating the proximal coronary-artery lumen has beenshown to improve support of the guide catheter and inner cathetercomposite system, thereby providing an opportunity for improved successfor device advancement through a difficult coronary lumen (Guideliner,Guidezilla, Telescope). Frequently, these inner catheters are only ableto navigate the proximal simpler portions of the artery anatomy, and donot allow the operator to obtain a position in the artery lumen thatprovides sufficient support to the guide catheter and inner cathetercomposite system. The inability to advance these inner catheters furtherinto a patient's vasculature is frequently as a result of the “razoreffect” caused by an overhang or transitions between the guidewire andthe inner-support catheter.

Generally, it is known that the introducer catheter must have an overalldiameter small enough to negotiate through a lumen of a vessel whileretaining an inner diameter (or “bore size”) large enough to accommodatea diagnostic, a therapeutic and/or an ablation device therethrough.Furthermore, since the path within a patient's vessel is often long andtortuous, steering forces must be transmitted over relatively longdistances. Accordingly, it is desirable for the introducer catheter tohave enough axial strength to be pushed through the patient'svasculature via a force applied at its proximal end (“pushability”). Itis also desirable for the introducer catheter to be capable oftransmitting a torque applied at the proximal end through to the distalend (“torqueability”). An introducer catheter should also have enoughflexibility to conform substantially to the patient's vasculature andyet resist kinking as it conforms to the patient's vasculature. Thesevarious characteristics are often in conflict with one another, withimprovements in one often requiring compromises in others. For example,increasing the bore size of an introducer catheter having a givenoverall diameter requires utilizing a thinner wall. As catheters areused in smaller and smaller passages and vessels, there is a growingneed to use introducer catheters that have a smaller outer dimension.However, a thin-walled introducer catheter is more likely to collapseupon itself or kink when a torque or a push force is applied at itsproximal end.

In order to facilitate the advancement of an introducer catheter (or anintroducer sheath) through a patient's vasculature, the application of apush force and/or torque at the proximal end of the introducer catheterand the ability to orient selectively the distal tip of the introducercatheter in a desired direction can permit medical personnel to advancethe distal end of the catheter and to position the distal portion of theintroducer catheter at a location of interest.

During use, an introducer catheter shaft should be capable oftransmitting torque and resisting compression. Substantial frictionalforces sometimes resist transmission of axial forces and torque alongthe length of the introducer catheter. In some cases, these forces maycause the introducer catheter shaft to twist about a longitudinal axisof the introducer catheter shaft, storing energy in the process in aspring-like fashion. If such energy is released suddenly, the distal endof the introducer catheter, which may have been deflected by a steeringmechanism, may be undesirably propelled with significant force.

With respect to resisting compression during use, it is important thatusers be able to advance the introducer catheter through a vessel,sometimes against significant frictional resistance, without undue axialor radial compression or snaking or fish-mouth distortion of theintroducer catheter shaft. Shaft compression may complicate thepositioning of the distal end of the introducer catheter shaft at adesired location for a medical procedure. In addition, medical personnelmay rely on tactile feedback to attain and verify proper positioning ofthe introducer catheter, and such feedback can be impaired by excessivecompressibility.

Accordingly, there is a need for improved devices, systems and methodsto deliver an introducer catheter or a sheath or a guide catheter or aninner catheter at a location of interest within a patient's body via abody lumen without damaging the lumen, or a body vessel, including atortuous lumen or vessel. The foregoing discussion is intended only toillustrate the present field and should not be taken as a disavowal orlimitation of claim scope.

SUMMARY OF THE INVENTION

The devices, systems, and methods for negotiating a patient'svasculature through lumens or vessels are described herein. Inparticular, the present invention provides improved devices, systems,and methods for procedures including diagnostic, therapeutic, andablative procedures in arterial and venous systems, as well as fornon-vascular lumen and vessel. A catheter system of the presentinvention comprises a transporter catheter and an introducer catheter.In an exemplary embodiment, a balloon at a distal tip of a transportercatheter facilitates the negotiation of the transporter catheter and/orassociated device or system through the body lumens of a patient. Thetransporter catheter may have at least one anchor balloon that anchorsthe transporter catheter to the introducer catheter. The anchor balloonprevents partially or fully the slippage or “pushback” of thetransporter catheter backwards into the lumen of the introducer catheterwhen the orienting balloon of the transporter catheter experiencesincreased resistance within the vasculature in the patient's body. Also,when the anchoring balloon is located proximate to the orientingballoon, the anchoring balloon acts as a stopper to prevent theorienting balloon from backing into the lumen of the introducer catheteras the catheter system is being maneuvered through the vasculature ofthe patient's body. It also prevents the orienting balloon frommigrating fully out of the introducer catheter, guide catheter or innercatheter when forward force is applied to the catheter system. In thedescription of the invention, the transporter catheter is described asbeing located inside the introducer catheter. The transporter cathetermay also be located inside any outer catheter, e.g., a sheath, a mothercatheter, a guiding catheter or a daughter catheter, to advance theouter catheter. An orienting balloon at a tip of the transportercatheter assists in the orientation and positioning of the transportercatheter, and an anchor balloon is used for anchoring the transportercatheter, e.g., anchoring the transporter catheter to an inner surfaceof an outer catheter as the user maneuvers the system comprising thetransporter catheter and the outer catheter through the patient'svasculature. The description and discussion regarding advancing theintroducer catheter also applies to advancing any other outer catheterthrough a patient's vasculature using a transporter catheter.

The catheter system of the present invention may be advanced through thevasculature of a patient's body by (a) pushing and/or torquing theintroducer catheter, (b) pushing and/or torquing the transportercatheter, or (c) pushing and/or torquing both the introducer catheterand the transporter catheter. If the user pushes and/or torques theintroducer catheter to advance the catheter system through thevasculature of the patient's body, then the anchor balloon of thetransporter catheter pushes and/or torques the transporter catheter asthe catheter system moves through the vasculature of the patient's body.If the user pushes and/or torques the transporter catheter to advancethe catheter system through the vasculature of the patient's body, theanchor balloon of the transporter catheter pulls and/or torques theintroducer catheter as the catheter system moves through the vasculatureof the patient's body. In both cases, the orienting balloon assists inorienting and maneuvering the catheter system through the vasculature ofthe patient's body.

An embodiment of the invention provides devices, systems, and methodsincluding a transporter catheter comprising a first tube having a lengthand defining a first open interior lumen, the first open interior lumenconnected to a first balloon located at a distal end of the transportercatheter, a second tube having a length and defining a second openinterior lumen, the second open interior lumen connected to a secondballoon located between the first balloon and the proximate end of thetransporter catheter. In another embodiment, the second balloon isproximate to the first balloon. In yet another embodiment, the distancebetween the proximal end of the first balloon and the distal end of thesecond balloon is less than half the length of the fully inflated firstballoon. In another embodiment, the distance between the proximal end ofthe first balloon and the distal end of the second balloon is less thanhalf the diameter of the fully inflated first balloon. In oneembodiment, the orienting balloon has length in the range from 15-40 mm.In another embodiment, the orienting balloon expands to diametersranging from 1.5-6 mm after inflation. In yet another embodiment, theorienting balloon expands to diameters in the range of 6-12 mm uponinflation.

In one embodiment of the invention, the device comprises a transportercatheter having a proximal end and a distal end, at least a firstballoon located at the distal end, substantially at a tip of thetransporter catheter, and at least a second balloon located between thedistal end and the proximal end of the transporter catheter. The firstballoon is an orienting balloon and the second balloon is an anchorballoon. The transporter catheter may include a single lumen or morethan one lumen. In one embodiment, the shaft of the transporter cathetermay be made from a polymer such as polytetrafluoroethylene (PTFE) orPEBAX (polyether block amide). In another embodiment, the shaft of thetransporter catheter may comprise a wire-based reinforcement embedded inthe polymeric shaft. In another embodiment, the shaft of the transportercatheter may comprise an inner layer and an outer layer. In oneembodiment, the inner layer may be made of a material more flexible thanthe material of the outer layer. In another embodiment, the outer layercomprises a material that has a lower flexural modulus and ahigher-yield strain than the material of the inner layer. In oneembodiment, the outer layer may comprise braided-wire assembly, saidbraided-wire assembly being formed by braiding a plurality of flat wiresor circular wires. The shaft of the transporter catheter may comprise aplurality of segments of varying hardness characteristics. The hardnessof the first segment of the shaft of the transporter catheter locatedbetween the orienting balloon and the anchor balloon may be less thanthe hardness of the second segment of the shaft between the anchorballoon and the proximal end of the catheter. In another embodiment, thehardness of a portion of the first segment of the shaft proximate to theorienting balloon may be less than the hardness of a portion of thefirst segment of the shaft proximate to the anchor balloon.

Another embodiment of the invention provides devices, systems, andmethods that comprise an introducer catheter that has a capability tomaneuver through the vasculature of a patient's body independently fromthe transporter catheter. Such introducer catheters are generally knownas “steerable-guide” catheters. One embodiment of the steerable-guidecatheter comprises at least a first handle assembly comprising a firstdeflecting mechanism coupled to a distal end portion of thesteerable-guide catheter to apply a deflecting force to bend the distalend portion, the first deflecting mechanism adapted to bend the distalend portion in a first articulated position, and a second deflectingmechanism coupled to the distal end portion of the steerable-guidecatheter to apply a deflecting force to bend the distal end portion, thesecond deflecting mechanism adapted to bend the distal end portion in asecond articulated position. The steerable-guide catheter furthercomprises at least an open interior lumen to accommodate passage of atransporter catheter to assist in the orientation and positioning of thesteerable catheter. The transporter catheter located inside thesteerable-guide catheter assists in orienting and positioning thesteerable catheter and compliments the functioning of the deflectingmechanisms to advance the steerable catheter smoothly. After thesteerable-guide catheter is positioned at the desired location, theorienting balloon and the anchor balloon in the transporter catheter aredeflated and the transporter catheter is removed from the interior lumenof the steerable-guide catheter.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a transporter catheter in accordancewith one embodiment of the present invention.

FIG. 2 is a perspective view of a transporter catheter having a firstsegment of the transporter catheter that is more flexible than a secondsegment of the transporter catheter.

FIG. 3 is a perspective view of a transporter catheter having multiplesegments of the transporter catheter with multiple degrees offlexibility.

FIG. 4a is a perspective view of a transporter catheter showing acontoured orienting balloon that facilitates smooth movement of theorienting balloon by reducing drag.

FIG. 4b is a perspective view of a transporter catheter showing aperfusion lumen to perfuse blood across the anchor balloon when theanchor balloon is inflated.

FIG. 4c is a perspective view of a transporter catheter showing aperfusion lumen to perfuse blood across the orienting balloon when theorienting balloon is inflated.

FIG. 5 is a perspective view of a transporter catheter with more thanone anchor balloons.

FIG. 6 is a perspective view of a transporter catheter having multiplesegments of varying degrees of hardness, with an anchor balloon presenton more than one segment.

FIG. 7 is a perspective view of a transporter catheter having ahydraulic system to advance the transporter catheter.

FIG. 8a-d are perspective views of modifications to the surface of theanchor balloon to enhance anchoring to the inner surface of anintroducer catheter.

FIG. 9 is a perspective view of a catheter system comprising atransporter catheter and an introducer catheter advancing through avasculature of a patient's body.

FIG. 10a-b is a schematic of forces acting on a wall of an introducercatheter when it is pushed at its proximal end or pulled at its distalend.

FIG. 11 is a perspective view of a catheter system comprising a mothercatheter, an inner support catheter and a transporter catheter advancingthrough an adverse arterial lumen.

FIG. 12 is a perspective view of a catheter system comprising a mothercatheter, an inner support catheter and a transporter catheter that hasadvanced through an adverse arterial lumen.

FIG. 13 is a perspective view of positioning of a stent in an adversearterial lumen using a catheter system comprising a mother catheter, aninner support catheter and a transporter catheter.

FIG. 14a-d are perspective views of modifications to the surface of theproximal portion of balloon to enhance anchoring of the proximal portionof the balloon to the inner surface of an introducer catheter.

FIG. 15 is a perspective view of a transporter catheter having a balloonwith a surface at its distal portion configured for smooth movementthrough a patient's vasculature and a surface at its proximal portionconfigured for anchoring to an outer catheter.

FIG. 16 is a perspective view of a transporter catheter having a balloonhaving a diameter at a distal portion which, upon inflation, is greaterthan an outer diameter of the outer catheter.

FIG. 17 is a perspective view of a transporter catheter having twoballoons, a first balloon with a surface at its distal portionconfigured for smooth movement through a patient's vasculature and asurface at its proximal portion configured for anchoring to an outercatheter, and a second balloon for additional anchoring to the outercatheter.

FIG. 18a-d are perspective cross-sectional views of shaft of someembodiments of a transporter catheter.

FIG. 19 is a perspective sectional view of a distal end portion of anembodiment of a transporter catheter that is steerable using pull-wires.

DETAILED DESCRIPTION OF THE INVENTION

Embodiments of the present invention are described below with referenceto the accompanying drawings. Systems using transporter cathetersaccording to the present invention provide improved maneuverability,flexibility, and kink resistance.

In reference to FIG. 1, catheter 100, comprises a shaft 101, having aproximal end 102, and a distal end 103, and a first lumen 104, a secondlumen 105, and a third lumen 106. First lumen 104 extends substantiallythe entire length of said shaft 101 and communicates with an orientingballoon 107 located at about the distal end 103 of said shaft 101.Second lumen 105 extends the entire length of said shaft 101 and allowsfor the placement of catheter 100 over guidewire 108. Third lumen 106communicates with an anchor balloon 109, which is located between theorienting balloon 107 and the proximal end 102 of the shaft 101. In oneembodiment, the anchor balloon is located proximal to the orientingballoon. In another embodiment, the first lumen 104 and the third lumen106 are diametrically opposed and each lumen extends substantiallyparallel to the longitudinal axis of the shaft 101. In anotherembodiment, the first lumen 104 and the third lumen 106 aresymmetrically disposed on either side of a longitudinally extendingplane bisecting the shaft into a first hemicylindrical portion and asecond hemicylindrical portion.

In another embodiment, the third lumen 106 communicating with the anchorballoon may be adapted to receive a removable stiffening stylet to easeinsertion by stiffening the catheter shaft. In yet another embodiment,two removable stiffening stylets may be inserted, one inserted in lumen104 and another inserted in lumen 106. Stiffening stylet(s) are insertedto extend substantially the entire length of member 101 until justproximal to anchor balloon 109. If two stylets are used, thepractitioner may insert one stylet further than the other to adjust theamount of stiffness as desired. In one embodiment, a stylet is notinserted beyond the anchor balloon.

Lumens 104, 105 and 106 are attached to Luer connectors 111 at theirproximal end. Said Luer connectors are then connected to syringes,valves etc. to provide for the introduction of balloon inflation media.In one embodiment, a radiopaque marker may be located along shaft 101,including distal end 103. In another embodiment, a radiopaque marker maybe located on the anchor balloon 109. In one embodiment, an imagingmarker is fixed to shaft 101 at its distal end portion, disposedslightly proximal from the tip 103 and in the area proximate to afront-end portion of the orienting balloon 107. In another embodiment,the imaging marker is fixed on the orienting balloon 107. In yet anotherembodiment, the imaging marker is fixed on the anchor balloon 109. Inone embodiment, the imaging marker is formed from a radiopaque material(e.g., gold, platinum, tungsten or alloys of these metals or from asilver-palladium alloy, or a platinum-iridium alloy). By so doing, it ispossible to confirm the location of the catheter and then to advance thecatheter 100 through a patient's vasculature, while monitoring suchadvancement using radiographic imaging and visualization. In oneembodiment, the shaft of the transporter catheter may have a lumen fromits proximal end to its distal end to infuse medication at the distalend by using a Luer connector at the proximal end.

The mechanical properties of segments of shaft 101 can be varied byadjusting and varying the properties of the cylindrical-braidstructure(s) and the polymeric materials (e.g., the dimension of thecylindrical-braid structure and/or durometers of the polymers).Additionally, the mechanical properties of the segments of shaft 101 canbe varied along the length of the shaft 101 in accordance with certainembodiments of the disclosure or can be substantially uniform along theentire length of the shaft 101 in accordance with other embodiments ofthe disclosure. In another embodiment, the shaft 101 is a monolithicelongate tubular shaft member having an inner core made of a firstmaterial and an outer layer made of a second material, the firstmaterial of the inner core defining lumens 104, 105 and 106 therein, thecross-sectional dimension of the first lumen 104 being uniform along thelength of the first lumen 104, the cross-sectional dimension of thesecond lumen 105 being uniform along the length of the second lumen 105,and the cross-sectional dimension of the third lumen 106 being uniformalong the length of the third lumen 106. In one embodiment, the tubularshaft member has an outer cross-sectional dimension that varies alongthe length of the tubular shaft member, the outer cross-sectionaldimension being greater at the proximal end than at the distal end.

In one embodiment, the shaft 101 may be provided with arigidity-imparting structure. In one embodiment, the rigidity-impartingstructure is provided using a blade. The blade may be formed of a metalwire or a synthetic-resin wire. In another embodiment, as shown in FIG.2, the rigidity-imparting structure is provided to the shaft over theentire length 201 of the shaft, except for the distal end portion 202 ofthe shaft from the anchor balloon 209 to the orienting balloon 207. Theanchor balloon 209 anchors the rigidity-imparted structure 201 to theinner surface of a lumen of the introducer catheter 224. In anotherembodiment, the rigidity-imparting structure is provided to the shaft101 in a range from the proximal end 102 of the transporter catheter tothe distal end 115 of the anchor balloon 109. In one embodiment, theshaft of the transporter catheter has a stiffness and a resistance tokinking. In another embodiment, the shaft of the transporter cathetercomprises an inner layer made preferably of a lubricious material, suchas polytetrafluoroethylene (PTFE), and an outer layer made preferably ofa thermoplastic elastomer, such as PEBAX (polyether block amide). Inanother embodiment, the inner and the outer layers are made of twodifferent melt-processable polymers. In another embodiment, the shaft ofthe transporter catheter may comprise more than two layers. In anotherembodiment, the inner and/or the outer layer comprises a particulateradiopaque filler material. In another embodiment, the outer surface ofthe shaft of the transporter catheter may have at least one radiopaquestrip along the length of the shaft and/or radiopaque markers atspecific locations of the shaft, e.g., at the distal end of thetransporter catheter.

In one embodiment, a wire-based reinforcement is embedded in the outerlayer. The wire-based reinforcement may be in the form of a plait matrixor a helical coil. The plait matrix may be braided. The plait-matrixlayer or the helical-coil layer may be bonded to the inner layer e.g.,by melting in place. In one embodiment, a plait-matrix layer or ahelical-coil layer is bonded to the inner layer by melting in placeusing a temporary shrink-wrap tubing as a forming member. Theplait-matrix layer or the helical-coil layer may also be known as thetorque-transfer layer. In another embodiment, the shaft comprises aplurality of sections with wire reinforcement in a form of aplait-matrix or a helical-coil layer extending continuously along atleast one length from the proximal end 102 of the shaft. In anotherembodiment, the shaft comprises a plurality of sections with theplait-matrix layer or the helical-coil layer extending continuously fromthe proximal end 102 of the shaft to the distal end 115 of the anchorballoon 109. In another embodiment, the shaft comprises a plurality ofsections with the plait-matrix layer or the helical-coil layer extendingcontinuously from the proximal end 102 of the shaft to the proximal endof the orienting balloon 107.

The plait matrix or the helical coil may be made of round wires,elliptical wires, flat wires or combination thereof. Wires of any othercross-sectional shapes may also be used. The wires may be made fromvarious materials, and may each be made of the same materials ormaterials with similar material properties, or different materialshaving different properties. As an example, such wires may be formedfrom stainless steel. The material of wires may be stiffer than theplastic materials forming the wall of the shaft. In one embodiment, theflat wire is at least about 0.003″ thick by about 0.007″ wide. Inanother embodiment, the wires may be made of Nitinol. In one embodiment,the braided-wire plait matrix has a proximal portion and a distalportion, the braided-wire plait matrix has a first density at theproximal portion and a second density at the distal portion, and whereinthe first density differs from the second density, the density of thebraided-wire assembly being measured in pixels of braids per inch of theshaft's longitudinal axis (PPI). In another embodiment, the PPI at theproximal portion of the braided-wire plait matrix is greater than thePPI at the distal portion of the braided-wire plait matrix. In anotherembodiment, the PPI is between about 10 and about 90. In yet anotherembodiment, the PPI is between about 5 and about 50. In anotherembodiment, the shaft of the transporter catheter comprises braided-wireplait matrix, wherein the PPI varies gradually from the proximal portionto the distal portion of the shaft whereby the stiffness of the shaftdiminishes gradually from the proximal portion to the distal portion. Inanother embodiment, the braided-wire plait matrix wraps around the innerlayer of the shaft. In another embodiment, the helical coil of wirewraps around the inner layer of the shaft. In yet another embodiment,the pitch of the helical coil at the proximal portion of the shaft issmaller than the pitch of the helical coil at the distal portion of theshaft. In another embodiment, the shaft of the transporter cathetercomprises a helical coil of wire, wherein the pitch increases graduallyfrom the proximal portion to the distal portion of the shaft whereby thestiffness of the shaft diminishes gradually from the proximal portion tothe distal portion.

The torque-transfer layer may be made of stainless steel (304 or 316)wire or other acceptable materials known to those of ordinary skill inthe art. In one embodiment, the torque-transfer layer is formed of abraided wire assembly comprised of flat wires, preferablystainless-steel wires including, for example, high tensilestainless-steel wires. The torque-transfer layer may be formed in anycombinations of braid patterns, including one-over-one (involving atleast two wires) or two-over-two (involving at least four wires)crossover patterns. In one embodiment, the torque-transfer layer mayutilize a varying braid density construction along the length of thetransporter catheter. For example, the torque-transfer layer may becharacterized by a first braid density at the proximal end of thetransporter catheter and then transition to one or more braid densitiesas the torque-transfer layer approaches the distal end of thetransporter catheter. The braid density of the distal end may be greateror lesser than the braid density at the proximal end. In one embodiment,the braid density at the proximal end is about 50 PPI and the braiddensity at the distal end is about 10 PPI. In another embodiment, thebraid density at the distal end is about 20-35% of the braid density atthe proximal end. The torque-transfer layer may be formed separately ona disposable core and subsequently slipped around an inner liner. One ormore portions of the torque-transfer layer may be heat-tempered andcooled before incorporation into the transporter shaft through methodsthat are known to those of ordinary skill. The action of heat temperingmay help to release the stress on the wire and help to reduce radialforces. In another embodiment, the torque-transfer layer may be braideddirectly on the inner liner. In yet another embodiment, thetorque-transfer layer may include at least one helical coil of steelwire. The distance between two consecutive spirals (known as the pitch)of the helical coil may vary along the length of the transportercatheter. For example, the torque-transfer layer may be characterized bya first pitch of helical coil at the proximal end of the transportercatheter and then transition to one or more pitches as thetorque-transfer layer approaches the distal end of the transportercatheter. The pitch of the helical coil at the distal end may be greateror less than the pitch of the helical coil at the proximal end. In oneembodiment, the pitch at the distal end is about 50-80% greater than thepitch at the proximal end.

In another embodiment of the invention shown in FIG. 3, the shaft has afirst flexible portion 301 disposed at the distal end of the shaft, asecond flexible portion 302, which is continuous with the first flexibleportion 301 and flexible, but that has a higher degree of hardness thanthe first flexible portion 301, and a flexible portion 303, which iscontinuous with the second flexible portion 302 and that has a higherdegree of hardness than the second flexible portion 302. In theembodiment shown in FIG. 3, the most flexible first flexible portion 301is between the orienting balloon 307 and the anchor balloon 309. Thesecond flexible portion 302 of the shaft is substantially covered by theanchor balloon 309. The third flexible portion 303 has a degree ofhardness higher than the hardness of the second flexible portion and thefirst flexible portion and extends from the proximal end 102 of thecatheter 100 to the proximal edge 116, 316 of the anchor balloon. Theflexibility of transporter catheter becomes stepwise lower from itsdistal end to its proximal end. Because the portion 301 of the shaftproximate to the orienting balloon 307 is flexible, the orientingballoon 307 is capable of passing through a curved portion of a vesselwith greater ease.

In one embodiment as illustrated in FIG. 4a , the distal end of theorienting balloon 407 is smooth and contoured to provide smooth movementof the orienting balloon. In another embodiment, the surface of theorienting balloon is coated with a friction-reducing coating. In anotherembodiment, the surface of the orienting balloon may have a wavy contouror other three-dimensional contours (not shown) when inflated to providechannels for perfusion of blood across the orienting balloon when theorienting balloon is inflated. In one embodiment as illustrated in FIG.4b , a perfusion lumen 402 is provided to perfuse blood across theanchor balloon 409 when the anchor balloon 409 is inflated. In anotherembodiment as illustrated in FIG. 4c , a perfusion lumen 405 is providedto perfuse blood across the orienting balloon 407 when the orientingballoon 407 is inflated. In one embodiment as illustrated in FIG. 5multiple anchor balloons 501, 502 may be present. In another embodimentillustrated in FIG. 6, at least one anchor balloon may be present ineach flexible portion of the shaft, e.g., a first anchor balloon 601 ispresent in a first flexible portion 611 and a second anchor balloon 602is present in a second flexible portion 612. The first anchor balloon601 is inflated using the first lumen 621 and the second anchor balloon602 is inflated using the second lumen 622, thereby the first anchorballoon 601 may be inflated or deflated independently from the inflationor deflation of the second anchor balloon 602, and vice versa. Inanother embodiment (not shown), a single lumen connects a plurality ofanchor balloons, whereby all anchor balloons inflate or deflatesimultaneously. In one embodiment, one or more anchor balloons may beanchored to the introducer catheter 624 depending on how the orientingballoon 607 advances through the vasculature of a patient's body. Morethan one anchor balloon may be inflated independently, if the orientingballoon experiences increased resistance. In another embodiment, anorienting balloon may be present at the distal edge of the introducercatheter. In another embodiment, an anchoring balloon may be located ina distal portion of the introducer catheter. An anchoring balloonlocated on the introducer catheter, upon inflation, may press againstthe outer surface of the transporter catheter to anchor the introducercatheter to the transporter catheter.

In yet another embodiment of the invention shown in FIG. 7, anintroducer catheter to which a transporter catheter is anchored isadvanced using hydraulic pressure. The system 70 comprises thetransporter catheter with a shaft 701, an orienting balloon 707 locatedat a distal end of the shaft 701, a hydraulic fluid lumen 721, hydraulicfluid 722, and a piston 723 movably disposed in the hydraulic fluidlumen and connected to the shaft 701 of the transporter catheter. Thepiston forms a seal with an interior surface of the hydraulic fluidlumen. A hydraulic driver, e.g., a syringe, that generates hydraulicpressure against the piston sufficient to advance the shaft 701 of thetransporter catheter, is used. The anchor balloon 709, which isconnected to the shaft 701, advances with the shaft. Upon inflation, theanchor balloon 709 is anchored to the inner surface 725 of theintroducer catheter 724, and thereby the advancement of the anchorballoon 709 also advances the introducer catheter 724 through apatient's vasculature. In one embodiment, the method of advancing theintroducer catheter a first distance inside a patient's vasculaturecomprises the following steps: (a) positioning the transporter catheterinside the introducer catheter; (b) inflating the orienting balloon; (c)adjusting the position of the transporter catheter whereby the orientingballoon is substantially outside the distal end of the introducercatheter; (d) inflating the anchor balloon to anchor the transportercatheter to the inside surface of the lumen of the introducer catheter;(e) applying hydraulic pressure to the piston to advance the introducercatheter. In another embodiment, after advancing the introducer cathetera first distance using hydraulic pressure, the introducer catheter isadvanced a second distance using the following method: (i) deflating theanchor balloon; (ii) reducing the hydraulic pressure; (iii)repositioning the transporter catheter inside the lumen of theintroducer catheter; (iv) inflating the anchor balloon to anchor thetransporter catheter to the introducer catheter; and (v) applyinghydraulic pressure again. Steps (i) to (v) may be repeated to continueadvancing the catheter system. In one embodiment, the inflation mediumcomprises a 1:2 mixture of contrast medium and normal saline solution.

In one embodiment, the length of the transporter catheter 100 may befrom about 100 cm to about 250 cm. The end use and the length of theintroducer catheter may determine the length of the transportercatheter. By way of illustration only and not by way of limitation, anddepending on physiology of a patient, a cerebral vasculature applicationmay warrant a transporter catheter length from about 100 cm to about 150cm; a coronary vasculature application may warrant a transportercatheter length from about 100 cm to about 160 cm in length; aperipheral vasculature application may warrant a transporter catheterlength from about 70 cm to about 100 cm in length; a renal vasculatureapplication may warrant a transporter catheter length from about 60 cmto about 90 cm in length; and a hepatic vasculature application maywarrant a transporter catheter from about 70 cm to about 100 cm inlength. In one embodiment, the outer diameter of the shaft 101 of thetransporter catheter 100 may range from about 2 French to about 12French, or higher. In another embodiment, the outer diameter of theshaft 101 of the transporter catheter 100 may be in the range from about4 mm to about 10 mm, or higher. However, the dimensions of the shaft 101of transporter catheter 100 may vary in accordance with variousapplications of the catheter system and size of the introducer catheter.

In one embodiment, the difference between the outer diameter of theshaft of the transporter catheter and the inner diameter of theintroducer catheter is less than 0.5 mm. In another embodiment, theouter diameter of the shaft of the transporter catheter is about 0.5 mmsmaller than the inner diameter of the introducer catheter. In anotherembodiment, the outer diameter of the shaft of the transporter catheteris about 1 mm to about 2 mm smaller than the inner diameter of theintroducer catheter. In yet another embodiment, outer diameter of theshaft of the transporter catheter is about half of the inner diameter ofthe introducer catheter. In another embodiment, the length of thetransporter catheter may be from about 20 cm to about 60 cm. In yetanother embodiment, the transporter catheter may have short lengths,e.g., in the range of about 3 cm to about 10 cm. In another embodiment,the transporter catheter may have length in the range of about 10 cm toabout 300 cm. In one embodiment, an orienting balloon may be locatedabout 3 mm from the distal tip of the transporter catheter. In anotherembodiment, the gap between the distal end of the anchor balloon and theproximal end of the orienting balloon may be in the range of about 2-10mm. In another embodiment, the gap between the distal end of the anchorballoon and the proximal end of the orienting balloon may be in therange of about 3-5 mm. In one embodiment, the outer diameter of theorienting balloon is about the same as the outer diameter of theintroducer catheter. In another embodiment, the outer diameter of theorienting balloon is greater than the outer diameter of the introducercatheter. In one embodiment, the orienting balloon is compliant. Inanother embodiment, the anchor balloon is non-compliant. In yet anotherembodiment, the orienting balloon is semi-compliant.

The distal end 103 of the shaft 101 may or may not be tapered. In oneembodiment, shaft 101 may have a taper, with the proximal end 102 havinglarger diameter than the distal end 103. The end use and the insidediameter of the introducer catheter may determine the outer diameter ofthe shaft 101. In one embodiment, shaft 101's inner diameter may rangefrom about 1 French to about 3 French, or higher. If shaft 101 is toreceive a guidewire 108, the inner diameter of the shaft will need to beproportioned accordingly. In one embodiment, guidewires up to 1.4 Frenchin diameter may be used. In another embodiment, guidewires may not beused in conjunction with the transporter catheter and the transportercatheter may not have lumen 105 for a guidewire. In one embodiment, thetransporter catheter may deliver the introducer catheter to the desiredlocation over a guidewire. In another embodiment, the transportercatheter may deliver the introducer catheter to the desire locationwithout the use of the guidewire. After the introducer catheter ispositioned, stylet(s) if present may be removed, then the orientingballoon and the anchor balloon may be deflated by means of a hand-heldsyringe or other means. In one embodiment, the transporter catheter isconfigured to track over a 0.009-0.014″ guidewire. In anotherembodiment, the transporter catheter may have a central lumen capable ofaccommodating guidewires of various diameters (e.g., guidewire with adiameter in the range 0.010″ to 0.065″). In one embodiment, thetransporter catheter may be structured in a “rapid exchange”configuration. In another embodiment, the transporter catheter may bestructured in an “over-the-wire” configuration. In another embodiment,the transporter catheter may not include an orienting balloon, and mayinclude at least one anchor balloon and/or may include at least onemechanical connector, said anchor balloon and/or mechanical connectorlocated at the distal end of the transporter catheter. The at least oneanchor balloon and/or the at least one mechanical connector anchors thedistal end of the transporter catheter to the outer catheter. In oneembodiment, the distal end of the transporter catheter is anchored tothe distal end of the outer catheter. In another embodiment, the atleast one anchor balloon and/or the at least one mechanical connectorare located in the distal end portion of the transporter catheter. Inyet another embodiment, the distal end portion of the transportercatheter is anchored to the distal end portion of the outer catheter.

The material for shaft 101, lumens 104, 105 and 106, orienting balloon107 may contain any one or more of the following additives. By way ofillustration only and not limitation, such additives may includeradiopaque fillers, slip additives, and hydrophilic coatings. In oneembodiment, silicon provides hydrophilic coating. In another embodiment,the material for shaft 101 comprises a particulate radiopaque fillermaterial. In one embodiment, an anchoring mechanism to anchor thetransporter catheter to the outer catheter is a friction-based mechanismbetween an outer surface of the transporter catheter and an innersurface of the outer catheter. In another embodiment, the anchor balloonmay be made of materials and/or coated with materials that providefrictional resistance to reduce slippage. In one embodiment, the anchorballoon may be made of polyurethane. In another embodiment, the anchorballoon may have serrations 801 as illustrated in FIG. 8a and/or raisedprojections 802 as illustrated in FIG. 8b to enhance the anchoringcapability of the anchor balloon to the inside of the introducer sheathafter the anchor balloon is inflated. The serrations and/or raisedprojections may have spiral shape 801 as shown in FIG. 8a , linear shape802 as shown in FIG. 8b , and other shapes, see for example, circularring shape 803 (see FIG. 8c ) or crisscross checkered shape 804 (seeFIG. 8d ). The projections may have inserts, e.g., wires. The wires orwire segments may be made from various materials, and may each be madeof the same materials or materials with similar material properties, ordifferent materials having different properties. As an example, suchwires or wire segments may be formed from stainless steel. The materialof wires may be stiffer than the materials forming the wall of theballoon. In another embodiment, the wires may be made of Nitinol. Theprojections enhance the anchoring capability of the anchor balloon tothe inside surface of the outer catheter, such as an introducercatheter, by coarsening the outer surface of the anchor balloon andanchoring the outer surface of the anchor balloon to the inner surfaceof the introducer catheter. The wire or wire segments forming theprojections may also have any cross-sectional geometric shape, includingfor example, circular, square, or triangular, and different projectionsmay have different cross-sectional shapes. Rounded shapes and/or smoothedges may help to prevent the wire or wire segment forming theprojection from perforating the wall of the anchor balloon. In oneembodiment, the wire or wire segments may be hollow to allow for passageof blood, thereby preventing occlusion of blood when the anchor balloonis inflated. In another embodiment, the inner surface of the outercatheter may be configured at a distal portion of the outer catheter toenhance frictional anchoring capability, e.g., the inner surface of theouter catheter at the distal portion may have a layer of material withhigher friction coefficient or may have knurling or serrations, or mayotherwise treated so as to increase frictional resistance in thatportion of the inner surface of the outer catheter.

In one embodiment, the wires or wire segments comprise a material thatis radiopaque (either a homogeneous material or a material that isnon-radiopaque, but is provided with a radiopaque coating), and thusvisible under fluoroscopy. Making the projections visible may also allowthe clinician to better discern the location and orientation of theanchor balloon, as well as the position of the anchor balloon beforeinflating and anchoring the balloon to the inner surface of theintroducer catheter. In another embodiment, the wall of the anchorballoon may comprise radiopaque particles.

In one embodiment, at least one mechanical connector is used to connectand anchor the transporter catheter and the introducer catheter. Inanother embodiment, the transporter catheter comprises a mechanicalconnector to anchor the transporter catheter to the inner surface of theintroducer catheter. In yet another embodiment, the transporter cathetercomprises a mechanical connector to anchor the transporter catheter tothe introducer catheter at or near the distal edge of the introducercatheter. In another embodiment, the transporter catheter and/or theintroducer catheter comprises at least one mechanical connector locatedin the distal portion of the transporter catheter and/or the distalportion of the introducer catheter. In one embodiment, a handle at theproximal end of the transporter catheter may be used to engage themechanical connector thereby enabling the anchoring of the transportercatheter to the introducer catheter. The handle at the proximal end ofthe transporter catheter may also be used to disengage the mechanicalconnector thereby allowing the removal of the transporter catheter fromthe introducer catheter. In another embodiment, a handle at the proximalend of the introducer catheter may be used to engage or disengage themechanical connector. In one embodiment, the mechanical connector is acircular cage of a matrix of round or flat wires wherein the diameter ofthe cage can be increased or decreased mechanically. In anotherembodiment, diameter of the cage may be increased or decreased, e.g., byrotating the handle at the proximal end of the transporter catheter,whereby when the handle is rotated in one direction, the cage is torquedto open and increase its diameter, and when the handle is rotated inother direction, the cage is torqued to close and decrease its diameter.The diameter of the cage is increased until it presses against the innersurface of the introducer catheter to anchor the transporter catheter tothe introducer catheter. In another embodiment, the mechanical connectormay be located on the introducer catheter and the mechanical connectorengages, e.g., presses against or locks the transporter catheter toanchor the introducer catheter to the transporter catheter.

In operation, a transporter catheter and an outer catheter may beadvanced from various arterial access sites, such as femoral, radial,brachial, axillary and carotid artery to gain percutaneous or operativeentry to arterial circulation. In one embodiment, once access is gained,a device is advanced from the access point via the aorta to the desiredtarget location for diagnostic or interventional procedure. Introductionof a catheter directly through an arteriotomy increases the possibilityof abrasion by the catheter edge against the inner arterial wall (alsoknown as intima). To reduce the risk of this possible interaction, aguidewire is typically first advanced through an arteriotomy. Theguidewire is typically a soft tipped, lower profile, flexible object,e.g., with a tip that is atraumatic. The placement of the guidewire andintroduction of the catheter over the guidewire centers the catheter inthe lumen of the artery and reduces the risk of abrasion of the catheteragainst the inner arterial wall. Despite the decreased risk to theintima of the arterial circulation because of guidewire placement andover-the-wire advancement, there still remains a risk of abrasion of theinternal wall of the arterial vessels by the overhang of the catheter inview of the fact that the guidewire is frequently significantly smallerin diameter compared to the catheter. This abrasive effect of thecatheter, which is generally termed as “razor defect”, may lead todislodgement of elements from the inner arterial wall, such asatherosclerotic as well as other debris. Liberated atherosclerotic, aswell as other debris, then may follow the arterial circulation and maylodge into a small distal branch based on the size of such debris. Thisevent may lead to tissue death or necrosis, which may lead to permanentorgan dysfunction, including ischemic necrosis of the bowel because ofan athero-embolic event, acute kidney injury because of a similarembolic event, as well as cerebrovascular events from liberation ofatheroma that may be caused by catheter transit through the ascendingaorta and the aortic arch. An embodiment of the present inventioncomprising the orienting balloon generally provides resolution of theoverhang, reducing the potential of the transitions, and hence reducingthe razor effect and lowering the risk of embolic events that may resultfrom catheter transit.

In operation as illustrated in FIG. 9, the orienting balloon 907 orientsand maneuvers the catheter system comprising the introducer catheter 924and the transporter catheter 901 through the curves of the vasculature931 in a patient's body. The orienting balloon 907 protrudes outside theintroducer catheter 924. In one embodiment, about 50% of the orientingballoon protrudes outside the introducer catheter 924. In anotherembodiment, more than 50% of the orienting balloon 907 protrudes outsidethe introducer catheter. In yet another embodiment, about 80% of theorienting balloon 907 protrudes outside the introducer catheter 924. Inanother embodiment, less than 50% of the orienting balloon 907 protrudesoutside the introducer catheter 924. In one embodiment, the orientingballoon may be inflated using a pressure from about 2 atmospheres toabout 10 atmospheres or higher. In another embodiment, the orientingballoon may be inflated to a pressure in the range 12-15 atmospheres. Inanother embodiment, the orienting balloon is inflated using a pressureof about 4 atmospheres. In one embodiment, the diameter of protrudingportion of the orienting balloon, that protrudes out from the introducercatheter may be larger than the outer diameter of the introducercatheter thereby substantially reducing or eliminating a potential razoreffect of the edge of the introducer catheter. The anchor balloon 909anchors the shaft of the transporter catheter 901 to the inner surfaceof the lumen of the introducer catheter 924. In one embodiment, aguidewire 908 may be present. In another embodiment, segment 911 betweenthe anchor balloon 909 and the orienting balloon 907 may be moreflexible than segment 901 of the transporter catheter. The cathetersystem may be advanced by pushing and/or torquing the introducercatheter 924, or the transporter catheter 901, or both. If the cathetersystem is advanced by pushing the introducer catheter, the wall of theintroducer catheter should have enough axial strength to be pushedthrough the patient's vasculature via a force applied at its proximalend (“pushability”). It is also desirable for the introducer catheter tobe capable of transmitting a torque applied at the proximal end alongthe length of the shaft through to the distal end (“torqueability”). Anintroducer catheter should also have enough flexibility to conformsubstantially to the patient's vasculature and yet resist kinking as itis pushed and/or torqued through the patient's vasculature and conformsto the patient's vasculature.

The wall of an introducer catheter 924 that is advanced by pushing theintroducer catheter is thick, and increasing the bore size of anintroducer catheter having a given overall diameter requires utilizing athinner wall. Now that catheters are used in smaller and smaller vesselsand body lumens, there is a growing need to use introducer cathetersthat have a smaller wall thickness. However, a thin-walled introducercatheter that is pushed through the patient's vasculature is more likelyto collapse upon itself or kink when a push force and/or torque isapplied at its proximal end. On the other hand, if the introducercatheter 924 is pulled through the patient's vasculature by an anchorballoon 909 of a transporter catheter, then the wall of the introducercatheter 924 may be relatively thinner. A thin wall may be used becausewhen the introducer catheter 924 is pulled through the patient'svasculature 931, a pulling tensile force is applied to the wall of theintroducer catheter 924. The tensile force has a stretching effect onthe wall of the introducer catheter and prevents kinking of the wall ofthe introducer catheter 924. On the other hand, if the introducercatheter 924 is pushed through the patient's vasculature, a compressiveforce is applied to the wall of the introducer catheter 924. If theintroducer catheter 924 experiences resistance and push-back from apatient's lumen, the compressive force could result in kinking of thewall of the introducer catheter 924. In one embodiment, pushing thetransporter catheter to advance the outer catheter to a desired locationin a patient's body results substantially in pulling the outer catheterto the desired location. In one embodiment, thickness of the wall of theintroducer catheter 924 is less than thickness of the wall of thetransporter catheter 901. In another embodiment, the wall of theintroducer catheter 924 is more flexible than the wall of thetransporter catheter 901. In another embodiment, the wall of thetransporter catheter 901 comprises a structure of wires to increase thestiffness of the wall of the transporter catheter. In anotherembodiment, the wall of the introducer catheter 924 does not comprise astructure of wires. In yet another embodiment, the introducer catheter924 in the proximal end portion of the introducer catheter may be moreflexible than the transporter catheter 901 in the proximal end portionof the transporter catheter. In one embodiment, thickness of the wall ofthe introducer catheter 924 is less than 0.2 mm. In another embodiment,the thickness of the wall of the introducer catheter 924 is less than0.1 mm. In yet another embodiment, the thickness of the wall of theintroducer catheter 924 is less than 0.5 mm. In one embodiment, theouter wall of the introducer catheter 924 is provided with a hydrophiliccoating to reduce friction between the outer wall of the introducercatheter 924 and the inner wall of a lumen 931 through which theintroducer catheter is being advanced.

FIG. 10a is a schematic of the forces that act on the introducercatheter when a user pushes the introducer catheter in direction 133 atthe proximal end of the introducer catheter 124 using a handle 132. Thepush force 151 on the wall of the introducer catheter has a horizontalcomponent 153 that advances the introducer catheter 124 through thevasculature 131 of the patient's body, and a vertical component 152 thatpresses the wall of the introducer catheter 124 against the wall of thevasculature 131. Because component 152 is directed towards the wall ofthe vasculature 131, the component 152 adds frictional resistance anddrag to the introducer catheter as it advances through the vasculature.Because of the additional frictional resistance, a greater push force isrequired, thereby requiring a thicker wall for the introducer catheterso that the introducer catheter does not collapse or kink. A greaterpush force also results in additional frictional resistance because of alarger vertical component 152. Total frictional resistance depends onthe contact area between the introducer catheter and the vasculature andtherefore depends in part on the length of the introducer catheter thatis inserted into the vasculature of a patient's body. Because of thecompounding of the frictional resistance with increase in push force,the length to which an introducer catheter can be pushed inside thevasculature may be limited.

FIG. 10b is a schematic of the forces that act on the introducercatheter as it is pulled by the anchor balloon of the transportercatheter when the user pushes the transporter catheter to advance theintroducer catheter. When a user pushes the transporter catheter 201 andwith it, its anchor balloon 209 in the direction 233, the anchor balloonexerts a pull force 251 on the wall of the introducer catheter 124. Thepull force 251 on the wall of the introducer catheter has a horizontalcomponent 253 that advances the introducer catheter 124 through thevasculature 131 of the patient's body, and a vertical component 252 thatpulls the wall of the introducer catheter 124 away from the wall of thevasculature 131. Because component 252 is directed away from the wall ofthe vasculature, the component 252 reduces the frictional resistance andthe drag on the introducer catheter as it advances through thevasculature. Consequently, a smaller push force is required on thetransporter catheter to advance the catheter system through thevasculature. Furthermore, because the walls of the introducer catheterexperience a pull force at the distal end (rather than a push force atthe proximal end), the possibility of kinking the wall of the introducercatheter is reduced, and a thinner wall may be used for the introducercatheter. The transporter catheter is removed after the introducercatheter is positioned at a desired location. Thus, for a given outerdiameter of an introducer catheter and by using a transporter catheterto advance the introducer catheter (or to advance any other outercatheter such as a sheath, a guide catheter, or a mother catheter), theuser may use an introducer catheter with a thinner wall, therebyproviding a larger diameter of its inner lumen. In one embodiment, thetransporter catheter may be used to pull the introducer catheter throughthe tortuosity of arteries, including celiac and mesenteric arteries. Inanother embodiment, a catheter system comprising the transportercatheter may be used to perform revascularization as well asdevascularization in cerebral circulation. In yet another embodiment, acatheter system comprising the transporter catheter may be used tocannulate a middle coronary vein, while implanting a CRT-D device orother devices. In one embodiment, a catheter system comprising thetransporter catheter may be used in a remote tele-robotic procedure,such as stroke management. In another embodiment, a system comprisingthe transporter catheter may be used to assist in the maneuvering andpositioning of an endoscopy tube or a colonoscopy tube inside a tract ofa digestive system of a patient.

In another embodiment (see FIGS. 11 and 12) comprising a mother catheter166 and an inner support catheter (daughter or child catheter) 165advanced on a guidewire 168, the inner support catheter 165 is advancedby placing a transporter catheter 161 inside a lumen of the innersupport catheter 165, with the transporter catheter having an orientingballoon 167 protruding from the tip of the inner support catheter andanother balloon 169, which is inside the lumen of the inner catheter 165providing anchoring. Using this multi-balloon transporter catheter 161to advance the inner catheter 165, the double balloon catheter compositemay be advanced through an adverse arterial lumen, beyond the stenosis162. After the inner support catheter has been successfully placedbeyond the stenosis 162, the transporter catheter is withdrawn afterdeflating the orienting and the anchor balloons. Then a stent 164 (seeFIG. 13) or other hardware may be placed through the inner supportcatheter 165 distal to the stenosis 162 or in another preferredposition. Subsequently the inner support catheter is withdrawn and thestent 164 may be then positioned usually by pulling the stent 164 to thesite of interest and deploying the stent 164 (FIG. 13). In oneembodiment, at least one hole may be provided in the structure of theinner support catheter to provide for perfusion of blood from outsidethe inner support catheter into the inner support catheter. In oneembodiment, the transporter catheter is inserted in the outer catheterand the orienting balloon is left partially protruding out of the tip ofthe outer catheter. The orienting balloon is then inflated withsufficient pressure using a fluid to achieve a certain diameter. In oneembodiment, the diameter of the inflated orienting balloon is at leastequal to the inner diameter of the outer catheter tip. In anotherembodiment, the diameter of the protruding portion of the orientingballoon is at least equal to the outer diameter of the outer cathetertip. In yet another embodiment, the diameter of the protruding portionof the orienting balloon is greater than the outer diameter of the outercatheter tip. A guidewire may be placed through the orienting balloonbefore, during or after inflation.

The inner support catheter may include a hydrophilic coating to reducefriction between the arterial lumen and the external surface of theinner support catheter. The wall of the inner support catheter can bemade thin whereby the diameter of the inner lumen of the supportcatheter is large and the outer dimensions of the inner support catheterconforms to the geometry of the coronary artery or other vessels.Because the transporter catheter is used to advance the inner supportcatheter, the inner support catheter does not require as much structure(such as larger wall thickness) to transmit longitudinal axial forces.

In one embodiment, the transporter catheter has at least one balloonthat functions as both the orienting balloon and the anchor balloon. Thetransporter catheter comprises a shaft, said shaft comprising a proximalend and a distal end; at least one balloon positioned adjacent to thedistal end of the shaft, the at least one balloon (see FIG. 14a-d )comprising a distal portion 855 and a proximal portion 856; the distalportion 855 of the at least one balloon, upon inflation, has a surfaceconfigured for smooth movement of the transporter catheter through apatient's vasculature, and the proximal portion 856 of the at least oneballoon, upon inflation, has a surface configured for anchoring thetransporter catheter to an outer catheter 224 (see FIG. 15); wherein, inoperation, the transporter catheter is located within a lumen 226 of theouter catheter 224 and the proximal portion 856 of the at least oneballoon upon inflation presses against an inner surface 857 of the lumenof the outer catheter thereby anchoring the transporter catheter 859near the distal end of the transporter catheter to the outer catheter224 near a distal end of the outer catheter (see FIG. 15); and,thereafter, when the transporter catheter is pushed and/or torqued toadvance the outer catheter to a desired location in the patient'svasculature, the transporter catheter in effect pulls the outer catheterto the desired location in a patient's vasculature. In anotherembodiment, an interface 858 between the distal portion and the proximalportion of the at least one balloon comprises a radiopaque marker. Inyet another embodiment, the distal portion of the at least one balloonis smooth and contoured to assist with smooth advancing of thetransporter catheter through the vasculature of the patient's body. Inone embodiment, the surface of the distal portion of the at least oneballoon is coated with a friction-reduction coating. In anotherembodiment, the proximal portion of the at least one balloon, afteranchoring to the inner surface of the lumen of the outer catheter,reduces slippage or pushback of the transporter catheter backwards intothe lumen of the outer catheter when the at least one balloonexperiences increased resistance within the patient's vasculature. Inyet another embodiment, the surface of the distal portion of the atleast one balloon comprises channels for perfusion of blood across theat least one balloon after the at least one balloon is inflated.

In one embodiment (see FIG. 16), a diameter of a distal portion 860 ofthe at least one balloon, upon inflation, is greater than an outerdiameter of the outer catheter, thereby substantially reducing oreliminating a potential razor effect of an edge of the outer catheter.In another embodiment, the proximal portion of the at least one balloonanchors the transporter catheter to the outer catheter using afriction-based mechanism between an outer surface of the proximalportion of the at least one balloon and an inner surface of the lumen ofthe outer catheter. In one embodiment, the friction-based mechanismcomprises at least serrations 851 (FIG. 14a ) and/or raised projections852 (FIG. 14b ), wherein the serrations and/or the raised projectionshave shapes comprising spiral 851 (FIG. 14a ), linear 852 (FIG. 14b ),circular 853 (FIG. 14c ), crisscrossed 854 (FIG. 14d ) or combinationsthereof. In another embodiment, the friction-based mechanism comprisesat least an outer layer covering at least partially the outer surface ofthe proximal portion of the at least one balloon that comes in contactwith the inner surface of the lumen of the outer catheter, said outerlayer comprising materials providing higher frictional resistance. Inone embodiment, the outer layer may comprise of etched polymericmaterial, e.g., etched polytetrafluoroethylene (PTFE) layer. In anotherembodiment, a layer of interlaced and/or braided wires may be embeddedon the outer surface of the balloon or the wires may be glued orotherwise connected to the outer surface of the at least one balloon.

In one embodiment, the transporter catheter comprises at least twoballoons (see FIG. 17). A first balloon 867 is located near the distalend of the transporter catheter, said first balloon 867 having a distalportion 855 that facilitates the orienting and the maneuvering of thetransporter catheter and a proximal portion 856 that anchors thetransporter catheter to the inner surface of the outer catheter 224. Asecond balloon 869 is an anchor balloon and is located near the firstballoon 867. In one embodiment of a method to advance the outer catheter224, both the first balloon and the second balloon may be inflatedseparately and independently to anchor the transporter catheter to theouter catheter. Next the transporter catheter is pushed and/or torquedto advance the outer catheter substantially near a location of treatmentin a patient's vasculature. Subsequently, the second balloon may bedeflated and upon further pushing and/or torquing of the transportercatheter, the first balloon pulls the distal end of the outer catheterto the location of the treatment site or beyond the treatment site.Subsequently the first balloon may be deflated and the transportercatheter removed from inside the outer catheter and then a treatmentsystem may be advanced inside the outer catheter to a location at thetreatment site or beyond the treatment site. In another embodiment ofthe method, the first and the second balloon may be deflated and thetransporter catheter may be removed after the outer catheter is advancedto a desired location.

FIG. 18a depicts a cross-sectional view of an embodiment of a shaft ofthe transporter catheter as shown in an embodiment depicted in FIG. 15.The transporter catheter is comprised of a tubular polymeric inner liner182, a torque-transfer layer 184, a core 186 comprised of amelt-processing polymer, and a heat-shrink layer 188. Lumen 191 providesfor passage of a guidewire and lumen 192 provides for inflating ordeflating the orienting balloon. FIG. 18b depicts a cross-section viewof an embodiment of a shaft of the transporter catheter as shown in anembodiment depicted in FIG. 17. Lumen 193 provides for inflating ordeflating the anchor balloon 869.

In one embodiment, the transporter catheter is steerable usingpull-wires. In another embodiment, the pull-wires comprise at least oneflat wire 190 disposed longitudinally along the length of thetransporter catheter (See FIGS. 18c and 18d ). A flat pull-wire 190typically has a rectangular cross section, though the cross section ofthe pull-wire need not be perfectly rectangular. In another embodiment,the cross-sectional shape of the pull-wire may be oval or circular. Atransporter catheter 100 (see FIG. 1) may include an elongated pull-wireextending through a pull-wire lumen of the shaft 101 of the transportercatheter 100 and terminating within the distal end portion of the shaft.In one embodiment, the pull-wire has a proximal end operativelyconnected to a handle assembly and a distal end anchored to the distalend portion of the transporter catheter. In another embodiment as shownin FIG. 19, the steerable transporter catheter may include a pull-wireanchor ring or steering ring 195 mechanically coupling a distal end ofthe pull-wire to the distal end portion of the transporter catheter. Inone embodiment, the steering ring 195 may be located at or near thedistal end 115 of the anchor balloon 109. In another embodiment, thesteering ring 195 may be located under the anchor balloon 109. In yetanother embodiment, the steering ring 195 may be located near theproximal or the distal end of the orienting balloon 107. In oneembodiment, the torque-transfer layer 184 may be disposed between theinner liner 182 and the pull-wire 190. In another embodiment, thetorque-transfer layer may be disposed between the pull-wire 190 and theheat-shrink layer 188. In another embodiment, the heat shrink layer maynot be present. In one embodiment the pull-wire 190 may be covered withlubricious materials before placement inside the transporter catheter.The lubricious materials comprise silicone and other lubriciousmaterials. In another embodiment, the pull-wire 190 may be smooth andcoated with a lubricious layer. In one embodiment, the pull-wire is madeof stainless steel. In another embodiment, more than one pull-wire maybe used. In another embodiment, two pull-wires may be used and spaced180 degrees apart (See, e.g., FIG. 18d ). In one embodiment, thepull-wires 190 are connected to at least one anchor ring 195 locatednear the distal end of the introducer (see FIG. 19). The proximal endsof the pull-wires 190 are operably connected to a steering mechanism(not shown) allowing for the steering of the transporter catheter 100during operation. In one embodiment, a pull-wire may be housed inside apolymeric tube 196 forming a lumen.

In one embodiment, the inner liner 182 is a polymeric material, such aspolytetrafluoroethylene (PTFE) or etched PTFE. The inner liner 182 mayalso be made of other melt-processing polymers, including, withoutlimitation, polyether block amides, nylon and other thermoplasticelastomers. Once such elastomer is Pebax (Pebax is a registered trademark and Pebax is made by Arkema, Inc.). Pebax of various durometers mayalso be used, including without limitation, Pebax 30D to Pebax 70D. Inone embodiment, the core 186 of the shaft is made of an extruded Pebaxor PTFE tubing. The melt-processing polymer of the core 186 occupies aplurality of voids of the wire mesh in the torque-transfer layer. Thecore 186 may also be made of other melt-processing polymers, including,without limitation, etched PTFE, polyether block amides, nylon and otherthermoplastic elastomers, of varying durometers. The core 186 may alsocomprise more than one layer, including, for example, two or more tubesof a melt-processing polymer (see FIG. 19).

In one embodiment, a method for intravascular treatment using atransporter catheter, comprises the steps of: (i) assembling a systemcomprising a transporter catheter and an outer catheter, the transportercatheter comprising a shaft having at least a first wall, a proximalend, a distal end and at least one internal channel for a guidewire, theouter catheter comprising a substantially cylindrical lumen having asecond wall, a proximal end and a distal end, the transporter catheterextending within the lumen of the outer catheter with the distal end ofthe transporter catheter substantially aligned with the distal end ofthe outer catheter, an anchoring mechanism displaced in an operativecoupling with the transporter catheter and/or the outer catheter wherebythe anchoring mechanism anchors at least a distal portion of thetransporter catheter to at least a distal portion of the outer catheter,the anchoring mechanism controllably actuated for anchoring or forremoval of anchoring of the transporter catheter to the outer catheter;(ii) extending a guidewire along the internal channel of the transportercatheter with a proximal end of the guidewire extending beyond theproximal end of the of the transporter catheter and a distal end of theguidewire extending beyond the distal end of the transporter catheter;(iii) advancing the distal end of the guidewire towards a desiredlocation in a vessel of interest at a treatment site; (iv) controllingsaid anchoring mechanism to anchor at least the distal portion of theouter catheter to at least the distal portion of the transportercatheter; (v) advancing the system by pushing and/or torquing at leastthe transporter catheter along the guidewire towards the treatment siteuntil the system is brought in alignment with or beyond the treatmentsite; (vi) actuating the anchoring mechanism to remove the anchor holdbetween the transporter catheter and the outer catheter; (vii) removingthe transporter catheter from inside the outer catheter; and (viii)advancing a treatment system inside the outer catheter to a location atthe treatment site or beyond the treatment site.

In one embodiment, the transporter catheter 100 is manufactured via anextrusion process. Given that extrusion processes are well known in theart, the general process is not discussed in detail herein. In general,the extrusion process begins by heating the polymer until melted. Themelted polymer is then forced under pressure through an extrusion tipand die. As the melted polymer exits the extrusion tip and die, it iscooled. A typical cooling method employs a water bath. The cooling stepsolidifies the device with the desired dimensions.

Shaft 101 and lumens 104, 105 and 106 may be manufactured using anycommercially available catheter materials. Materials may include,without limitation, polyethylene, polyamide, and urethane. It may bealso possible to use polyolefin, such as polypropylene; polyestersincluding polyamide and polyethylene terephthalate; fluorine-basedpolymer including PTFE (polytetrafluoroethylene); PEEK (polyether etherketone); polyimide; synthetic resin elastomers including an olefinicelastomer (e.g., a polyethylene elastomer and a polypropyleneelastomer), polyamide elastomer, styrenic elastomer (e.g., astyrene-butadiene-styrene copolymer, a styrene-isoprene-styrenecopolymer, a styrene-ethylene butylene-styrene copolymer); polyurethane,urethane-based elastomer, and fluorine-based elastomer; syntheticrubber, including urethane rubber, silicone rubber, and butadienerubber. The material chosen will depend on the end use of the catheter,the size of the vessel to be accessed, and/or whether or not a stylet orstylets will be used to assist during insertion and advancement of thecatheter system. The desired end use will determine the degree ofstiffness, flexibility, strength and/or slipperiness of the material(s)to be used. Orienting balloon 107 and anchor balloon 109, may bemanufactured using any commercially available balloon materials.Materials include, without limitation, latex, silicone,ethylvinylacetate, and urethane.

It should be appreciated that several of the above-disclosed and otherfeatures and functions, or alternatives or varieties thereof, may bedesirably combined into many other different systems or applications.Also, it should be appreciated that various alternatives, derivatives,modifications, variations or improvements thereof or therein may besubsequently made by those skilled in the art, which are also intendedto be encompassed by the following claims.

In the description above, for the purposes of explanation, certainrequirements and certain details have been included in order to providean understanding of the embodiments. It will be apparent however, to oneskilled in the art, that one or more other embodiments may be practicedwithout some of the requirements or details. The particular embodimentsdescribed are not provided to limit the invention, but merely toillustrate it. The scope of the invention is not to be determined by thespecific examples provided above. In other instances, well-knownstructures, devices, and operations have been shown in block diagramform or without detail in order to avoid obscuring the understanding ofthe description. Where appropriate, reference numerals or terminalportions of reference numerals have been repeated among the figures toindicate corresponding or analogous elements, which may optionally havesimilar characteristics.

It should also be appreciated that reference throughout thisspecification to “one embodiment”, “an embodiment”, “one or moreembodiments”, or “different embodiments”, for example, means that aparticular feature may be included in the practice of the invention.Similarly, it should be appreciated that in the description variousfeatures are sometimes grouped together in a single embodiment, figure,or description thereof for the purpose of streamlining the disclosureand aiding in the understanding of various inventive aspects. Thismethod of disclosure, however, is not to be interpreted as reflecting anintention that the invention requires more features than are expresslyrecited in each claim. Rather, as the following claims reflect,inventive aspects may lie in fewer than all features of a singledisclosed embodiment. In another situation, an inventive aspect mayinclude a combination of embodiments described herein or in acombination of fewer than all aspects described in a combination ofembodiments.

The invention claimed is:
 1. A transporter catheter comprising: a shaft,said shaft comprising a proximal end and a distal end; at least oneballoon formed on the shaft and positioned adjacent to the distal end ofthe shaft, said at least one balloon comprising a distal portion and aproximal portion; the distal portion of said at least one balloon, uponfull inflation, having a surface configured for smooth movement of thetransporter catheter through a patient's vasculature, and the proximalportion of said at least one balloon, upon full inflation, having asurface configured for anchoring the transporter catheter to an outercatheter; wherein, in operation, the transporter catheter is locatedwithin a lumen of the outer catheter and the proximal portion of the atleast one balloon upon full inflation is configured to press against aninner surface of the lumen of the outer catheter thereby anchoring thetransporter catheter near the distal end of the transporter catheter tothe outer catheter near a distal end of the outer catheter, such thatthe transporter catheter is configured to be pushed and/or torqued toadvance the outer catheter to a desired location in the patient'svasculature by pulling the outer catheter to the desired location in thepatient's vasculature.
 2. The transporter catheter of claim 1, whereinan interface between the distal portion and the proximal portion of theat least one balloon comprises a radiopaque marker.
 3. The transportercatheter of claim 1, wherein the transporter catheter is steerable usingat least one pull-wire disposed longitudinally along a length of thetransporter catheter.
 4. The transporter catheter of claim 1, whereinthe distal portion of the at least one balloon is contoured to assistwith smooth advancing of the transporter catheter through the patient'svasculature.
 5. The transporter catheter of claim 1, wherein the surfaceof the distal portion of the at least one balloon is coated with afriction-reduction coating.
 6. The transporter catheter of claim 1,wherein the proximal portion of the at least one balloon is configuredto reduce slippage or pushback of the transporter catheter backwardsinto the lumen of the outer catheter when the at least one balloonexperiences increased resistance within the patient's vasculature. 7.The transporter catheter of claim 1, wherein the surface of the distalportion of the at least one balloon comprises channels for perfusion ofblood across the at least one balloon after the at least one balloon isfully inflated.
 8. The transporter catheter of claim 1, wherein adiameter of the distal portion of the at least one balloon, upon fullinflation, is greater than an outer diameter of the outer catheter,thereby substantially reducing or eliminating a potential razor effectof an edge of the outer catheter.
 9. The transporter catheter of claim1, wherein the shaft comprises a plurality of segments having varyingdegrees of stiffness.
 10. The transporter catheter of claim 9, wherein adegree of stiffness of the varying degrees of stiffness at the proximalend of the shaft is greater than a degree of stiffness of the varyingdegrees of stiffness at the distal end of the shaft.
 11. The transportercatheter of claim 10, wherein the varying degrees of stiffness of theshaft gradually reduces from the proximal end to the distal end.
 12. Thetransporter catheter of claim 1, wherein the proximal portion of the atleast one balloon anchors the transporter catheter to the outer catheterusing a friction-based mechanism between an outer surface of theproximal portion of the at least one balloon and the inner surface ofthe lumen of the outer catheter.
 13. The transporter catheter of claim12, wherein the friction-based mechanism comprises at least serrationsand/or raised projections.
 14. The transporter catheter of claim 13,wherein the serrations and/or raised projections have shapes comprisinglinear, spiral, circular, crisscrossed or combinations thereof.
 15. Thetransporter catheter of claim 1, wherein the shaft comprises at least aninner layer and an outer layer.
 16. The transporter catheter of claim15, wherein the inner layer of the shaft is made of a material moreflexible than a material of the outer layer.
 17. The transportercatheter of claim 16, wherein the outer layer comprises a braided-wireassembly, said braided-wire assembly being formed by braiding aplurality of flat wires, circular wires, or combinations thereof. 18.The transporter catheter of claim 17, wherein the braided-wire assemblyhas a proximal portion and a distal portion, and wherein the braidedwire assembly has a first density at the proximal portion and a seconddensity at the distal portion, and wherein the first density differsfrom the second density.
 19. The transporter catheter of claim 18,wherein the first density at the proximal portion of the braided-wireassembly is greater than the second density at the distal portion of thebraided-wire assembly.
 20. A transporter catheter comprising, a shaft,said shaft comprising a proximal end and a distal end; at least oneballoon formed on the shaft positioned adjacent to the distal end of theshaft, said at least one balloon comprising a distal portion and aproximal portion; the distal portion of said at least one balloon, uponfull inflation, having a surface configured for smooth movement of thetransporter catheter through a patient's vasculature, and the proximalportion of said at least one balloon, upon full inflation, having asurface configured for anchoring the transporter catheter to an outercatheter; at least one pull-wire disposed longitudinally along a lengthof the transporter catheter for steering the transporter catheter; and adegree of stiffness at the proximal end of the shaft that is greaterthan a degree of stiffness at the distal end of the shaft; wherein, inoperation, the transporter catheter is located within a lumen of theouter catheter and the proximal portion of the at least one balloon uponfull inflation is configured to press against an inner surface of thelumen of the outer catheter thereby anchoring the transporter catheternear the distal end of the transporter catheter to the outer catheternear a distal end of the outer catheter, such that the transportercatheter is configured to be pushed and/or torqued to advance the outercatheter to a desired location in the patient's vasculature by pullingthe outer catheter to the desired location in patient's vasculature.